This project is aimed at developing an implantable polymodal electrode system (PES) that could be used to obtain volumetric electrophysiological data useful for the optimization of stereotactically targeted neurosurgical interventions such as RF ablation and deep brain stimulation. Such interventions are rapidly emerging as treatments for a variety of intractable neurological conditions, including movement disorders, pain and epilepsy. Increasingly electrophysiological techniques such as microrecording and micro- and macrostimulation are employed as an adjunct to anatomically based target selection derived from CT and/or MRI scans. The work proposed herein would test the feasibility of the development of an array of polymodal electrodes with user-selectable, individually controllable elements small enough to function as both microelectrodes for recording single units as well as microstimulation sites. Initial Phase I work will include an investigation of the necessary design and fabrication parameters, (i.e., electrode materials, insulation types, microwire configuration, coatings) in order to manufacture a PES alpha prototype. The feasibility of extruding microwires from a central core shaft in a controlled and reproducible manner will also be confirmed during Phase I. Information gained from Phase I work will then be used in Phase II to fabricate PES beta prototypes for use in animal testing. PROPOSED COMMERCIAL APPLICATION: The recent success of various functional neurosurgical approaches like radiofrequency ablation or chronic deep brain stimulation for the treatment of movement disorders, epilepsy and intractable pain has established these techniques as viable alternatives when other medical options are unsuitable. An integral prt of these procedures is the use of intracranial neural recording and stimulation techniques for target localization. As more functional neurosurgical procedures are performed each year, there is a growing need for new and innovative electrode technology that is safer and provides the neurosurgeon with better diagnostic and therapeutic capabilities.